What is an Enzyme?

Enzymes are biological catalysts - catalysts are substances that increase the rate of chemical reactions without being used up. Enzymes are also proteins that are folded into complex shapes that allow smaller molecules to fit into them. The place where these substrate molecules fit is called the active site. If the shape of the enzyme changes, its active site may no longer work. We say the enzyme has been denatured. They can be denatured by high temperature or extremes of pH.

What is Pepsin?

Pepsin is an enzyme in the stomach that begins the digestion of proteins by splitting them into smaller pieces. It is a gastric protease; pepsin is secreted in an inactive form, pepsinogen, which is activated by stomach acid. enzyme produced in the mucosal lining of the stomach that acts to degrade protein. Pepsin is synthesized in an inactive form by the stomach lining; hydrochloric acid, also produced by the gastric mucosa, is necessary to convert the inactive enzyme and to maintain the optimum acidity ( pH 1-3) for pepsin function. Pepsin and other proteolytic enzymes are used in the laboratory analysis of various proteins; pepsin is also used in the preparation of cheese and other protein-containing foods.

What is a pH?

pH is a measurement of the acidity or alkalinity (base) of a solution. When substances dissolve in water they produce charged molecules called ions. Acidic water contains extra hydrogen ions (H+) and basic water contains extra hydroxyl (OH-) ions. pH is measured on a scale of 0 to 14. Neutral water has a pH of 7. Acidic water has pH values less than 7, with 0 being the most acidic. Likewise, basic water has values greater than 7, with 14 being the most basic. A change of 1 unit on a pH scale represents a 10 fold change in the pH, so that water with pH of 6 is 10 times more acidic than water with a pH of 7, and water with a pH of 5 is 100 times more acidic than water with a pH of 7. You might expect rainwater to be neutral, but it is actually somewhat acidic. As rain drops fall through the atmosphere, they dissolve gaseous carbon dioxide, creating a weak acid. Pure rainfall has a pH of about 5.6